161660899 has 2 divisors, whose sum is σ = 161660900. Its totient is φ = 161660898.

The previous prime is 161660893. The next prime is 161660929. The reversal of 161660899 is 998066161.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-161660899 is a prime.

It is a super-2 number, since 2×161660899² = 52268492530976402, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (161660893) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80830449 + 80830450.

It is an arithmetic number, because the mean of its divisors is an integer number (80830450).

Almost surely, 2^161660899 is an apocalyptic number.

161660899 is a deficient number, since it is larger than the sum of its proper divisors (1).

161660899 is an equidigital number, since it uses as much as digits as its factorization.

161660899 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 139968, while the sum is 46.

The square root of 161660899 is about 12714.5939376765. The cubic root of 161660899 is about 544.7555495480.

The spelling of 161660899 in words is "one hundred sixty-one million, six hundred sixty thousand, eight hundred ninety-nine".